System and Method for Managing Carryback Thresholds in Surface Haulage

ABSTRACT

A machine routing and planning system for mobile machines at a work site includes a plurality of haul trucks, at least one loading machine, and a controller. The controller is configured to generate an initial material movement plan based upon an initial number of loading machines and haul trucks and the initial carryback threshold, and generate initial movement command signals to operate the loading machines and haul trucks at the work site based upon the initial material movement plan. The controller is further configured to generate a modified material movement plan based upon a modified number of loading machines and haul trucks and the modified carryback threshold, and generate modified movement command signals to operate the loading machines and haul trucks at the work site based upon the modified material movement plan.

TECHNICAL FIELD

This disclosure relates generally to mobile haul machines for movingmaterial and, more particularly, to a system for operating haul machinesthrough the management of carryback thresholds with respect to carrybackmaterial within the dump body of the haul machine.

BACKGROUND

Machines such as haul trucks or haul machines are used in variousindustries to transport or move material from one location to another.When using a haul truck to haul material, under certain conditions, someof the material may adhere or stick to the interior surface of the dumpbody of the haul truck after each dumping operation. The materialremaining in the dump body may be referred to by different terms such ascarry back, residual load, or deadbed.

Carryback material remaining in the dump body is undesirable because itreduces machine productivity. More specifically, carryback materialreduces the effective capacity (e.g., volume) of the dump body thusrequiring a greater number of haul cycles to move a desired amount ofmaterial from the loading site to the dump site. Further, the increasedweight of the dump body due to carry back material also reduces the fuelefficiency of the haul trucks. Each of these decreases the efficiency ofthe material moving process.

U.K. Patent Application No. 2537590 discloses a tipper truck havingtipper body that may be pivoted by a hydraulic cylinder to empty thetipper body. A pressure parameter is measured relating to the hydraulicpressure of the hydraulic cylinder. A residual load may be measuredwithin the tipper body based upon the pressure parameter.

The foregoing background discussion is intended solely to aid thereader. It is not intended to limit the innovations described herein,nor to limit or expand the prior art discussed. Thus, the foregoingdiscussion should not be taken to indicate that any particular elementof a prior system is unsuitable for use with the innovations describedherein, nor is it intended to indicate that any element is essential inimplementing the innovations described herein. The implementations andapplication of the innovations described herein are defined by theappended claims.

SUMMARY

In a first aspect, a machine routing and planning system for mobilemachines at a work site includes a plurality of haul trucks, at leastone loading machine, and a controller. Each haul truck has a dump bodywith an interior surface for hauling material. The at least one loadingmachine being configured to load material into the dump body of eachhaul truck. The controller is configured to access an initial number ofloading machines and haul trucks operating at the work site, access aninitial carryback threshold for the interior surface of each haul truckbased on the initial number of loading machines and haul trucksoperating at the work site, generate an initial material movement planbased upon the initial number of loading machines and haul trucks andthe initial carryback threshold, and generate initial movement commandsignals to operate the loading machines and haul trucks at the work sitebased upon the initial material movement plan. The controller is furtherconfigured to access a modified number of loading machines and haultrucks operating at the work site, access a modified carryback thresholdfor the interior surface of each haul truck based on the modified numberof loading machines and haul trucks operating at the work site, generatea modified material movement plan based upon the modified number ofloading machines and haul trucks and the modified carryback threshold,and generate modified movement command signals to operate the loadingmachines and haul trucks at the work site based upon the modifiedmaterial movement plan.

In another aspect, a method of machine routing and planning for mobilemachines at a work site includes accessing an initial number of loadingmachines and haul trucks operating at the work site, with the haultrucks having a dump body for hauling material, and the loading machinesbeing configured for loading material into the dump body of each haultruck, and accessing an initial carryback threshold for an interiorsurface of each haul truck based on the initial number of loadingmachines and haul trucks operating at the work site. The method furtherincludes generating an initial material movement plan based upon theinitial number of loading machines and haul trucks and the initialcarryback threshold, generating initial movement command signals tooperate the loading machines and haul trucks at the work site based uponthe initial material movement plan, accessing a modified number ofloading machines and haul trucks operating at the work site, accessing amodified carryback threshold for the interior surface of each haul truckbased on the modified number of loading machines and haul trucksoperating at the work site, generating a modified material movement planbased upon the modified number of loading machines and haul trucks andthe modified carryback threshold, and generating modified movementcommand signals to operate the loading machines and haul trucks at thework site based upon the modified material movement plan.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a diagrammatic illustration of a work site at which theprinciples disclosed herein may be used;

FIG. 2 depicts a perspective view of a loading machine and a haul truckoperating at the work site of FIG. 1;

FIG. 3 depicts a diagrammatic rear view the haul truck of FIG. 2 with aperception monitor positioned above the dump body of the haul truck;

FIG. 4 depicts a side view of the haul truck of FIG. 2;

FIG. 5 depicts a rear perspective view of the dump body of the haultruck of FIG. 4;

FIG. 6 depicts a side view of an excavator for use with the systemsdisclosed herein;

FIG. 7 depicts a perspective view of a water cannon for use with thesystems disclosed herein;

FIG. 8 depicts a flowchart illustrating the operation of an aspect ofthe systems disclosed herein;

FIG. 9 depicts a flowchart illustrating the operation of a second aspectof the systems disclosed herein;

FIG. 10 depicts a flowchart illustrating the operation of a third aspectof the systems disclosed herein; and

FIG. 11 depicts a flowchart illustrating the operation of a fourthaspect of the systems disclosed herein.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary work site 100 at which one or moremachines 10 may operate in an autonomous, a semi-autonomous, or a manualmanner to move material from one location at the work site 100 toanother location at the work site or to a further location at a locationremote from the work site. Work site 100 may be a portion of, forexample, a mine site, a construction site, a road work site, a landfill,a quarry, a forest, or any other type of site. As depicted in FIG. 1, anexcavator 11 is being used to load material onto a haul truck 40although any type of machine may be used to load the material and anytype of machine may be used to subsequently transport the material.

Work site 100 may include multiple locations designated for particularpurposes. For example, a first location may be designated as a loadlocation 101 at which one or more loading machines, such as an excavator11 or other machines, operate to fill one or more haul trucks 40 withmaterial. A second location may be designated as a dump location 102 atwhich the haul trucks 40 discharge or dump their payloads. In thedisclosed embodiment, the dump location 102 is positioned at an edge ofa steep incline, crest, or cliff area often referred to as a high wall103. In this embodiment, haul trucks 40 may operate to discharge theirpayloads over the edge of the high wall 103. Haul trucks 40 may follow amain travel path 104 that generally extends between load location 101and dump location 102.

Dump location 102 may be divided into groupings 105 of dump targets 106at which haul trucks 40 may discharge their payloads. It is contemplatedthat dump location 102 may have any number of groupings 105. By havingmultiple groupings 105 at dump location 102, more than one haul truck 40may operate at dump location 102 at the same time without trafficproblems and significant time delays.

A control system 115 indicated generally by an arrow in FIG. 1associated with the work site 100 may operate to control certain aspectsof the machine operation at the work site and also communicateinformation between the machines and between the machines and a backoffice or remote system 120. The control system 115 may be a stand-alonesystem or may include other systems including those within or associatedwith the various machines 10 such as the control systems of the machinesdescribed below

Control system 115 may include components at the work site 100 and mayalso include components located remotely from the work area. As aresult, the functionality of control system 115 may be distributed sothat certain functions are performed at the work site 100 and otherfunctions are performed remotely, such as at a remote operations center.The control system 115 may include a communications system includingboth a wireless communications system 121 at a command center 122 and awired communications systems (not shown) for transmitting signalsbetween components.

The control system 115 may include an electronic control module orcontroller 116 that may receive various input signals from wirelesscommunications system 121, wired communications systems (not shown),control systems and sensors associated with machines 10, or from anyother source. The control system 115 and controller 116 may control andprovide input to the operation of various aspects of the work site 100including the specific tasks and operations performed by machines 10.

The controller 116 may be an electronic controller that operates in alogical fashion to perform operations, execute control algorithms, storeand retrieve data and other desired operations. The controller 116 mayinclude or access memory, secondary storage devices, processors, and anyother components for running an application. The memory and secondarystorage devices may be in the form of read-only memory (ROM) or randomaccess memory (RAM) or integrated circuitry that is accessible by thecontroller. Various other circuits may be associated with the controller116 such as power supply circuitry, signal conditioning circuitry,driver circuitry, and other types of circuitry.

The controller 116 may be a single controller or may include more thanone controller disposed to control various functions and/or features ofthe control system 115. For example, the controller 116 may includemachine controllers associated with machines 10. The term “controller”is meant to be used in its broadest sense to include one or morecontrollers and/or microprocessors that may be associated with the worksite 100 and/or the machines 10 and that may cooperate in controllingvarious functions and operations at the work site and of the machines.The functionality of the controller 116 may be implemented in hardwareand/or software without regard to the functionality. The controller 116may rely on one or more data maps relating to the operating conditionsand environment at the work site 100 as well as characteristics andcapabilities of the machines 10 that may be stored in the memory ofcontroller. Each of these data maps may include a collection of data inthe form of tables, graphs, and/or equations.

The excavator 11 has multiple systems and components that cooperate tomove material in a desired manner. The excavator 11 may include animplement system 12 comprising a swing member or platform 13, anundercarriage 14, and a linkage assembly 16 including a work implementconfigured as a bucket 17. The platform 13 may be rotatably disposed onthe undercarriage 14 and may include an operator station 18 from whichan operator may control some or all of the operations of the excavator11. Rotation of the platform 13 relative to the undercarriage 14 may beeffected by a swing motor indicated generally at 19.

The undercarriage 14 may be a structural support for one or moretraction devices 20 configured as ground engaging tracks operative toallow translational motion of the excavator 11 across a work surface andthus permit the implement system 12 to be a movable implement system.Alternatively, the traction devices 20 may be configured as wheels,belts, or other traction devices known in the art.

A prime mover 15 may provide power for the operation of the excavator11. In one embodiment, the prime mover 15 may embody a combustionengine, such as a diesel engine, a gasoline engine, a gaseous fuelpowered engine (e.g., a natural gas engine), or any other type ofcombustion engine known in the art. The prime mover 15 may alternativelyembody a non-combustion source of power, such as an electrical sourceincluding a fuel cell or a power storage device such as a batterycoupled to a motor. The prime mover 15 may provide a rotational outputto drive the traction devices 20, thereby propelling the excavator 11.The prime mover 15 may also provide power to other systems andcomponents of the excavator 11.

The linkage assembly 16 may include one or more linkage membersconfigured to move the bucket 17. In one example, the linkage assembly16 may include a boom member 22 and a stick member 23. A first end ofthe boom member 22 may be pivotally connected to the platform 13, and asecond end of the boom member may be pivotally connected to a first endof the stick member 23. The bucket 17 may be pivotally or movablyconnected to a second end of stick member 23.

Each linkage member may include and be operatively connected to one ormore actuators such as hydraulic cylinders. More specifically, the boommember 22 may be propelled or moved along a path by one or more boomhydraulic cylinders 25. The stick member 23 may be propelled by a stickhydraulic cylinder 26. Rotation of the bucket 17 relative to the stickmember 23 may be effected by work implement hydraulic cylinders 27. Thelinkage members may translate or rotate in a plane that is generallyorthogonal to the work surface. Other types of actuators arecontemplated such as electric motors, pneumatic motors, or any otheractuation devices.

The excavator 11 may include and be controlled by an excavator controlsystem 30 as shown generally by an arrow in FIG. 2 indicatingassociation with the machine. The excavator control system 30 mayinclude an electronic control module or controller such as an excavatorcontroller 31 that controls the operation of various aspects of theexcavator 11 including the drivetrain and the hydraulic systems. Theexcavator control system 30 and the excavator controller 31 may beidentical or similar in structure and operation to the control system115 and the controller 116 of the work site, respectively, describedabove and their descriptions are not repeated herein. The excavatorcontrol system 30 and the excavator controller 31 may be located on theexcavator 11 and may also include components located remotely from theexcavator such as on any of the other machines 10 at the work site 100or at a command center 122. The functionality of excavator controller 31may be distributed so that certain functions are performed on theexcavator 11 and other functions are performed remotely.

The excavator 11 may be equipped with a plurality of sensors thatprovide data indicative (directly or indirectly) of various operatingparameters of the machine and/or the operating environment in which themachine is operating. The term “sensor” is meant to be used in itsbroadest sense to include one or more sensors and related componentsthat may be associated with the excavator 11 and that may cooperate tosense various functions, operations, and operating characteristics ofthe machine and/or aspects of the environment in which the machine isoperating.

An implement system pose sensing system 32, as shown generally by anarrow in FIG. 2 indicating association with the excavator 11, includesan implement system pose sensor 33 to sense the position and orientation(i.e., the heading, pitch, roll or tilt, and yaw) of the implementsystem 12 relative to the work site 100. The position and orientationare sometimes collectively referred to as the pose. The implement systempose sensor 33 may include a plurality of individual sensors thatcooperate to generate and provide pose signals to the excavatorcontroller 31 indicative of the position and orientation of theimplement system 12.

In one example, the implement system pose sensor 33 may include one ormore sensors that interact with a positioning system such as a globalnavigation satellite system or a global positioning system to operate asa pose sensor. In another example, the implement system pose sensor 33may further include a slope or inclination sensor such as a pitch anglesensor for measuring the slope or inclination of the implement system 12relative to a ground or earth reference. The excavator controller 31 mayuse the implement system pose signals from the implement system posesensor 33 to determine the pose of the implement system 12 within worksite 100. In other examples, the implement system pose sensor 33 mayinclude an odometer or another wheel rotation sensing sensor, aperception based system, or may use other systems such as lasers, sonar,or radar to determine all or some aspects of the pose of implementsystem 12.

In an embodiment, the implement system pose sensor 33 may include firstpose sensor for determining the position of an aspect of the excavators,such as the platform 13 or the undercarriage 14, together with aplurality of angle sensors indicated generally at 34 located near one ormore joints of the linkage members (i.e., the boom joint between theplatform 13 and the boom member 22, the stick joint between the boommember 22 and the stick member 23, and the implement joint between thebucket 17 and the stick member 23). In some instances, the overallposition of the excavator 11 may be determined as a function of theundercarriage 14. In such case, the plurality of angle sensors 34 mayinclude an angle sensor to determine the relative angle between theplatform 13 and the undercarriage 14. The angle sensors 34 may includeinertial measurement units, rotary encoders, potentiometers, or otherangle or sensing devices for measuring the relative angular position ofcomponents.

In an alternate embodiment, the angle sensors 34 may measure thedisplacement of an actuator and the joint angles may be calculated basedupon the position of the actuators and the dimensions of the linkagemembers. In another alternate embodiment, any or all of the anglesensors 34 may be configured to measure an angular velocity or anangular acceleration rather than angular position. Regardless of thetype of the angle sensors 34, the excavator controller 31 may use outputsignals from the angle sensors to determine the position of each linkagemember and the bucket 17 relative to the platform 13 and/orundercarriage 14.

The positions of the components of the excavator 11 including theimplement system 12 may be determined based upon the kinematic model ofthe machine together with the dimensions of the platform 13,undercarriage 14, boom member 22, stick member 23, and bucket 17, aswell as the relative positions between the various components. Morespecifically, the excavator controller 31 may include a data map thatidentifies the position of each component of the excavator 11 based uponthe relative positions between the various components. The excavatorcontroller 31 may use the position of the platform 13 and/orundercarriage 14 together with the dimensions and the positions of thevarious components to determine the position of each component of theexcavator 11 relative to the work site 100. The operatingcharacteristics and kinematics of the excavator 11 may be stored withinor accessed by the excavator controller 31 or any other controller suchas controller 116.

Referring to FIGS. 2-3, a perception system 35 may be disposed orpositioned proximate to the bucket 17. The perception system 35 mayinclude one or more systems such as an optical system (e.g., a camerasystem), a thermal or infrared imaging system, a radar system, a LIDARsystem, and/or any other desired system that operates with associatedperception sensors to detect the configuration of material within thedump body 44 of a haul truck 40 as described in further detail below. Inan embodiment, the perception system 35 may be configured as an opticalsystem and include perception sensors such as a camera system 36 havinga single camera or multiple cameras. In some embodiments, it may bedesirable to provide a light source 37 to improve, add or emphasize thecontrast and/or otherwise improve the performance of the camera system36 with respect to the analysis of the dump body 44.

The perception sensors such as the camera system 36 may generateperception signals or data that is received by the excavator controller31 or the controller 116 and used to determine the position of carrybackmaterial on the interior surface 46 of the dump body 44 of a haul truck40 as described below. To do so, the perception system 35 may be used togenerate an electronic map and/or images of the interior surface 46 ofthe dump body of a haul truck 40. The perception system 35 may use thecamera system 36 or any other sensors mounted to generate perceptiondata. In an embodiment, each camera of the camera system 36 may bemounted on the excavator 11 at a relatively high vantage point such ason a cantilevered beam 38 extending from the stick member 23 adjacentthe bucket 17. The perception sensors such as camera system 36 may bepositioned at other locations as desired.

Referring to FIG. 4, a diagrammatic illustration of a haul truck 40 forhauling or transporting material is depicted. The haul truck 40 includesa frame 41, and a prime mover such as engine 42 operatively connected todrive wheels 43 to propel the machine. The haul truck 40 may use anytype of machine propulsion and drivetrain mechanisms includinghydrostatic, electric, or a mechanical drive.

A payload container or dump body 44 may be pivotally mounted on frame 41and configured to carry material. Referring to FIG. 5, the interiorsurface 46 of the dump body 44 may have one of many differentconfigurations. The interior surface 46 may be defined by theconfiguration of the lower surface 47, opposite sidewalls 48, and frontwall 49. Referring back to FIG. 4, actuators such as hydraulic cylinders50 may extend between the frame 41 and the dump body 44. The actuatorsmay be actuated to dump material within the dump body 44 as desired.

The haul truck 40 may include a cab 51 that an operator may physicallyoccupy and provide input to control the machine. Cab 51 may include oneor more input devices (not shown) through which the operator may issuecommands to control the propulsion and steering of the machine as wellas dump the dump body 44.

The haul truck 40 may include and be controlled by a haul truck controlsystem 52 as shown generally by an arrow in FIG. 3 indicatingassociation with the machine. The haul truck control system 52 mayinclude an electronic control module or controller such as a haul truckcontroller 53 that controls the operation of various aspects of the haultruck 40 including the drivetrain and the hydraulic systems. The haultruck control system 52 and the haul truck controller 53 may beidentical or similar in structure and operation to the control system115 and the controller 116 of the work site, respectively, describedabove and their descriptions are not repeated herein. The haul truckcontrol system 52 and the haul truck controller 53 may be located on thehaul truck 40 and may also include components located remotely from thehaul truck such as on any of the other machines 10 at the work site 100or at a command center 122. The functionality of haul truck controller53 may be distributed so that certain functions are performed on thehaul truck 40 and other functions are performed remotely. The operatingcharacteristics and reference profile of the haul truck 40 may be storedwithin or accessed by the haul truck controller 53 or any othercontroller such as controller 116.

The haul truck 40 may be equipped with a plurality of sensors indicatedgenerally that provide data indicative (directly or indirectly) ofvarious operating parameters of the machine. As stated above withrespect to the excavator 11, the term “sensor” is meant to be used inits broadest sense to include one or more sensors and related componentsthat may be associated with the haul truck 40.

The plurality of sensors of haul truck 40 may include a haul truck posesensing system 54 similar in some respects to the implement system posesensing system 32 described above. As shown in FIG. 4, the haul truckpose sensing system 54 may include a haul truck pose sensor 55 having aplurality of individual sensors that cooperate to generate and providepose signals to the haul truck controller 53 indicative of the positionand orientation (i.e., the heading, pitch, roll or tilt, and yaw) of thehaul truck 40 relative to the work site 100. The sensors associated withthe haul truck 40 may include sensors that are identical or similar tothose described above with respect to the excavator 11 and thus thedescriptions thereof are not repeated herein. In addition, haul truck 40may include a dump body angle sensor 56 to determine the position of thedump body 44 relative to frame 41 or some other point of reference. Thehaul truck pose sensing system 54 in combination with the dump bodyangle sensor 56 may operate as a dump body pose sensor to determine thepose of the dump body 44 relative to the work site 100.

The haul truck control system 52 may also include a payload estimationsystem generally indicated at 57. The payload estimation system 57 maydetermine an estimate of the payload within the dump body 44 of the haultruck 40. In an embodiment, the payload estimation system 57 may operateby measuring the pressure on the hydraulic cylinders 50.

The excavators 11 and the haul trucks 40 operating at the work site 100may be configured to be operated autonomously, semi-autonomously, ormanually. In case of semi-autonomous or manual operation, the machinesmay be operated by remote control and/or by an operator physicallylocated within their cab. If a machine is configured to operate via aremote control system, a visual image system (not shown) such as acamera system may be provided for generating visual images indicative ofa point of view relative to the machine. The visual image signals may betransmitted wirelessly through a wireless network system 121 to a systemremote from the machines such as an off-board control system 115.

Inasmuch as operations performed at the work site 100 and by theexcavator 11 and the haul truck 40 may be planned or controlled by anyof the excavator control system 30, the haul truck control system 52, orthe control system 115, or any combination thereof, as well as theexcavator controller 31, the haul truck controller 51, or the controller116, or any combination thereof, references herein to systems andoperations of the control system 115 and/or the controller 116 may referto systems and operations of any of the excavator control system 30, thehaul truck control system 52, or the control system 115, or anycombination thereof, as well as the excavator controller 31, the haultruck controller 51, or the controller 116, or any combination thereof.

The control system 115 may include a carryback monitoring system 60(FIG. 1) operative to monitor in an autonomous or semi-autonomous mannerthe amount of carryback material within the dump body 44 of each haultruck 40 and determine whether a carryback threshold has been reached.Upon determining that the dump body 44 is carrying an amount ofcarryback material that exceeds a carryback threshold, the haul truck 40may be identified or designated for cleaning out the interior surface 46to remove the carryback material. To determine whether the amount ofcarryback material exceeds the carryback threshold, the current profileof the interior surface 46, which includes the shape of the interiorsurface as modified by the carryback material, may be compared to areference profile of the interior surface that includes no carrybackmaterial (i.e., is completely empty).

Dump bodies 44 may be designed or configured based upon any combinationof goals in view of the materials to be hauled. Such goals may includemaximizing payload, maximizing durability, maximizing hauling efficiency(i.e. maximizing tons/hr), and/or minimizing spillage. Accordingly, thereference profile of the interior surface 46 of the dump body 44 may bedifferent for each haul truck 40. Examples of aspects of the interiorsurface 46 of a dump body 44 that may vary from one dump body to anotherinclude: 1) whether the lower surface 47 is flat or another shape (e.g.,“ducktail”); 2) the slope of the lower surface 47; 3) the height of thesidewalls 48 relative to the lower surface 47; 4) the slope or anglebetween the lower surface 47 and the sidewalls 48; 5) the height of thefront wall 49 relative to the lower surface 47; 6) the slope or anglebetween the lower surface 47 and the front wall 49; and 7) the amount ofcurvature at each intersection or junction between components such asbetween the lower surface 47 and the sidewalls 48, between the lowersurface 47 and the front wall 49, and between the sidewalls 48 and thefront wall 49.

In addition, the interior surface 46 may undergo changes over time sothat it may be desirable to periodically update the reference profiles.In one example, aspects of the interior surface may be modified due todamage or repairs. In another example, a liner may be applied or removedfrom the interior surface.

The carryback monitoring system 60 may store a reference profile foreach haul truck 40 operating at the work site. The reference profilesmay take the form of an electronic map or three-dimensional computerimage. In some embodiments, the reference profile of each haul truck 40may be stored together with identifying information such as a codecorresponding to each truck as part of the data maps of the excavatorcontroller 31 on-board the excavator 11, within the haul truckcontroller 53 on-board the haul truck, or at a remote location such aswithin the controller 116.

In one embodiment, the carryback monitoring system 60 may operate bypositioning a perception system 35, such as the camera system 36 locatedadjacent the bucket 17 of the excavator 11, at a position above theinterior surface 46 of the dump body 44 of a haul truck 40. Perceptiondata may be captured by the perception system 35 and used to create ordefine an electronic map of the current profile of the interior surface46. When using this process, the perception data is captured while thedump body 44 is empty, such as prior to emptying the first bucket ofmaterial into the dump body 44. To do so, the perception system 35 ispositioned above the interior surface 46 of the dump body 44 so that thecaptured perception data includes the present or current interiorsurface of the dump body. As a result, the current profile of theinterior surface 46, including the carryback material, is captured bythe perception system.

The pose of the perception system 35 may be determined by the implementsystem pose sensor 33 together with the kinematics of the implementsystem 12. Thus, the implement system pose sensor 33 together with thekinematics of the implement system 12 may operate as a perception systempose sensor that generates perception system pose signals or data. Theperception data captured by the perception system 35 may then becombined with the pose of the perception system to generate anelectronic image or map of the field of view of the perception systemrelative to the work site 100. This electronic map will include thecurrent profile of the interior surface 46 of the dump body 44.

The pose of the dump body 44 may be determined by the haul truck posesensor 55 as described above. By knowing the pose of the dump body 44and the reference profile of the interior surface 46 of the dump body,an electronic map or model of the reference profile relative to the worksite 100 may be generated.

After determining the pose of the current profile of the interiorsurface 46 of the dump body 44 and the pose of the reference profile,the carryback monitoring system 60 may compare the current profile tothe reference profile to determine the amount of carryback materiallocated within the dump body. If the amount of carryback materialexceeds a threshold amount (e.g., a percentage of the volume or weightof the dump body 44), the haul truck 40 may be designated as requiringcleaning or emptying of the carryback material. In some instances, thelocation of the carryback may also be a factor in determining whether aclean out operation is desired or required.

In one example, the haul trucks 40 may be sent to a clean out stationsequentially upon exceeding the carryback threshold. In another example,upon a haul truck 40 being designated for clean out, the haul truck maybe routed to a specific dump location 102 to facilitate subsequent cleanout. For example, the clean out station 107 may be near a specific dumplocation or the clean out station may be between the dump location 102and the next load location 101 such at a clean out station 108 along themain travel path 104.

Other embodiments are contemplated. For example, the perception system35 may be disposed adjacent the dump location 102 rather than on theexcavators 11 so that each haul truck 40 is inspected after its mostrecent dump cycle. By positioning the perception system 35 adjacent thedump location 102, the current profile of each dump body 44 may begenerated or determined after the most recent loading cycle. This mayresult in a more accurate current profile and a more efficient clean outoperation.

In another embodiment, the perception system 35 may be located near theclean out station 108 along the main travel path 104 with each haultruck 40 passing the perception system on its way back to the loadlocation 101. From the foregoing, it may be understood that theperception system 35 may be located at any position at the work site100. The perception system 35 may be positioned at a locationsufficiently high to permit scanning the interior surface 46 of the dumpbody 44. A pose sensing system may be associated with each perceptionsystem regardless of its location to permit the generation of anelectronic map of the carryback material on the interior surface 46 ofthe dump body 44 being scanned.

In still another embodiment, a first perception system 35 and a secondperception system 125 (together with a pose sensing system) may beprovided. In one embodiment, the first perception system 35 may bedisposed on each excavator 11 and the second perception system 125disposed either adjacent the clean out station 107, 108. The firstperception system 35 may be operative to generate a first currentprofile of the interior surface 46 of the dump body 44 sufficient todetermine whether a clean out operation is desired or necessary and thesecond perception system 125 may be operative to generate a secondcurrent profile that is used during the clean out process. In someinstances, the first perception system 35 may be less complex oraccurate than the second perception system 125, so as to reduce costs orsimplify its operation while the second perception system may be morecomplex or accurate to provide a more accurate current profileimmediately prior to the clean out operation.

In an additional embodiment, the payload detection system 57 may be usedto determine whether a clean out operation is desired or required and asingle perception system 35 provided to generate the current profileused for the clean out operation.

The excavator control system 30 may further include a carryback cleanout system 61 (FIG. 1) operative to clean out or remove the carrybackmaterial from the interior surface 46 of a dump body 44 in an autonomousor semi-autonomous manner. The carryback clean out system 61 may be usedto clean out a dump body 44 regardless of the manner in which a cleanout designation has been made. For example, such determination may bemade in an automated manner such as with the carryback monitoring system60 or manually by an observer such as an operator of a excavator 11. Inanother example, the control system 115 may monitor the number of loadand dump cycles of each haul truck 40 since the previous clean out cycleand designate each haul truck for clean out after a specified number ofcycles. The specified number may be dependent upon the characteristicsof the material being hauled and the configuration of the interiorsurface 46 of the dump body 44, and production objectives andperformance goals as described below.

Regardless of the manner in which a clean out designation has been made,upon designating or scheduling a haul truck 40 for a clean outoperation, the haul truck may be moved to a clean out location andpositioned adjacent a clean out mechanism. In one embodiment, a cleanout mechanism may be configured as a relatively small excavator 111depicted in FIG. 6 with a clean out implement such as a bucket 17. Thesmall excavator 111 maybe similar or identical to the excavator 11described above and have the same functionality. Like reference numbersrefer to identical or similar components and descriptions thereof arenot repeated herein for purposes of brevity. In another embodiment asdescribed in more detail below, the clean out mechanism may be a waterbased system such as a water cannon 70 (FIG. 7) and the clean outimplement may be a nozzle 73.

In an embodiment, the carryback clean out system 61 may operate bypositioning the haul truck 40 requiring clean out adjacent the excavator111 at the clean out location. In some instances, it may be desirable tofully extend the hydraulic cylinders 50 operatively connected to thedump body 44 to fully raise the dump body to its dump position whileperforming the clean out operation. In other instances, it may bedesirable to only partially extend the hydraulic cylinders 50 to onlypartially raise the dump body from its haul position on the frame 41.The pose of the dump body 44 may be determined by the dump body posesensor defined by a combination of the haul truck pose sensing system 54and the dump body angle sensor 56. In other words, the pose of the dumpbody may be determined based upon the pose of the haul truck 40 and therelative angle of the dump body 44 relative to the frame 41.

Using the pose of the dump body 44, the reference profile, and thecurrent profile of the interior surface 46, the carryback clean outsystem 61 may determine the pose of the reference profile and thelocation of the carryback material on the interior surface of the dumpbody. The location of the carryback material may be stored as anelectronic model within the controller 116.

The excavator 111 may be moved to a desired position adjacent the dumpbody 44. The pose of the excavator 111 may be determined by theimplement system pose sensor 33. The position of the bucket 17 of theexcavator 111 may be determined based upon the pose of the excavator andthe kinematic model of the excavator. Using the kinematic model of theexcavator 111 and the pose of the excavator as well as the pose of thereference model of the interior surface 46 of the dump body 44, thecarryback clean out system 61 may determine a plan for automated removalof the carryback material. The plan for removing the carryback materialmay include moving a work implement such as the bucket 17 along a pathformed or defined by a plurality of cycles or routes to move the workimplement about the interior surface 46 of the dump body 44 about theinterior surface 46 to physically engage or contact the carrybackmaterial that has adhered to the interior cavity.

The carryback clean out system 61 may utilize one or more optimizationparameters to prioritize or weigh different aspects of the clean outprocess when generating the clean out path for the work implement. Forexample, such optimization parameters may include the shortest clean outtime, maximizing the amount of material cleaned out of the dump body 44,or minimizing the likelihood of contact between the bucket 17 and theinterior surface 46 of the dump body. In one embodiment, the carrybackclean out system 61 may optimize the path of the bucket 17 to clean outthe interior surface 46 in the least amount of time. In doing so, thepath may be designed to maximize the amount of time spent movingmaterial while minimizing the amount of time spent repositioning thebucket 17 for each material removal cycle. In another embodiment, thecarryback clean out system 61 may optimize the path of the bucket 17 toclean out the interior surface 46 as thoroughly as possible. In stillanother embodiment, the carryback clean out system 61 may optimize thepath of the bucket 17 to avoid or minimize the likelihood of contactbetween the bucket and the interior surface 46. In other embodiments, acombination of two or more optimization parameters may be used in orderto provide a desired balance between the various optimizationparameters.

In some instances, it may be desirable to position the excavator 111 ina central position relative to a longitudinal axis of the dump body 44and perform the entire clean out process. In other instances, it may bedesirable to position the excavator 111 in a first position relative tothe dump body 44, move the bucket 17 along a first portion of the pathto perform a desired number of clean out cycles of the clean outprocess. The excavator may then be repositioned to a second positionrelative to the dump body and spaced from the first position where thebucket 17 is moved along a second portion of the path to perform furtherclean out cycles. The process of moving the excavator 111 to additionalpositions and moving the bucket 17 may repeated as desired until theclean out implement or tool has moved along the entire planned path.

If desired, an additional perception system or inspection system may bedisposed adjacent the clean out location to determine whether asufficient amount of material has been cleaned out from the dump body44. In such case, a new current profile may be generated and compared tothe reference profile. In an example, the interior surface 46 may besufficiently cleaned out if the difference between the current profileand the reference profile is less than the carryback threshold or someother threshold. If additional clean out is desired, a new materialremoval plan with a new work implement path may be generated.

In another embodiment, the carryback clean out mechanism may embody arobotic arm mechanism (not shown) that is fixed to a transportable base.The robotic arm mechanism may resemble the implement system 12 describedabove without the propulsion system.

In still another embodiment, the work site 100 may include a rockbreaker (not shown) such as a hydraulic hammer or another similardevice. In such case, the rock breaker may be used as a carryback cleanout mechanism by moving the rock breaker about a desired path withoutactuating the secondary function such as the hammer mechanism. Forexample, the bucket 17 of an excavator similar to that depicted at 111may be replaced by a hydraulic hammer (not shown).

In another embodiment, the carryback clean out system 61 may operate ina manner similar to that described above but may substitute a watercannon, water jet or another fluid based system to clean out theinterior surface 46 of the dump body. Referring to FIG. 7, an exemplarywater cannon 70 is depicted. The water cannon 70 may include an inlet 71in which water enters the cannon, a motor 72 for pressurizing the water,and a nozzle 73 from which the water exits the cannon. The nozzle 73 maybe configured to control the flow in a desired pattern.

The nozzle 73 may be operatively connected to a drive system 74operative to control the orientation and/or position of the nozzle todirect the flow of water along a desired path. For example, the drivesystem 74 may include motors for controlling movement of the nozzle 73along any axes as well as an additional motor for controlling the sizeof the aperture of the nozzle. The inlet 71 may be connected to a supplyline 75 that is further connected to a water supply. In someembodiments, water supply may be a tank (not shown) of a mobile watersupply truck (not shown). In other embodiments, the water supply may bea tank fixed at the work site 100 or take any other form.

The water cannon 70 may be associated with a water cannon pose sensingsystem 78 including a water cannon pose sensor 79 having a plurality ofindividual sensors that cooperate to generate and provide pose signalsindicative of the position and orientation (i.e., the heading, pitch,roll or tilt, and yaw) of the water cannon 70 relative to the work site100.

The carryback clean out system 61 utilizing the water cannon 70 mayoperate as described above with respect to the excavator 111 bypositioning the haul truck 40 requiring clean out at a desired locationrelative to the water cannon 70 and positioning the dump body at adesired angular orientation through the use of the hydraulic cylinders50.

The pose of the dump body 44 may be determined by the dump body posesensor. Using the pose of the dump body 44, the reference profile, andthe current profile of the interior surface 46, the carryback clean outsystem 61 may determine the pose of the reference profile and thelocation of the carryback material on the interior surface of the dumpbody. The water cannon 70 may be positioned as desired adjacent the dumpbody 44. The pose of the water cannon 70 may be determined with thewater cannon pose sensor 79.

Using the pose of the water cannon 70 as well as the pose of thereference model of the interior surface 46 of the dump body 44, thecarryback clean out system 61 may determine a plan for removing thecarryback material. The plan for removing the carryback material mayinclude directing the nozzle 73 of the water cannon 70 along a pathformed or defined by a plurality of cycles or routes to direct waterinto the interior surface 46 of the dump body 44 to dislodge thecarryback material that has adhered to the interior cavity.

As described above, optimization parameters may be used to prioritize orweigh different aspects of the clean out process. As also describedabove, in some instances it may be desirable to position the watercannon 70 in a central position relative to the dump body 44 and performthe entire clean out process. In other instances, it may be desirable toposition the water cannon 70 in a first position relative to the dumpbody 44, perform a desired number of clean out cycles, and thenreposition the water cannon to one or more subsequent positions relativeto the dump body and perform further clean out cycles at the subsequentpositions until the interior surface 46 has been sufficiently cleanedout.

The control system 115 may further include a machine routing andplanning system 117 (FIG. 1) that operates to determine when haul trucks40 should be routed through the cleanup process. The machine routing andplanning system 117 functions to plan the operation and routes of themachines 10 operating at the work site 100.

For example, a work site 100 such as a mine site may include a pluralityof loading machines such as excavators 11 and a plurality of haul trucks40 operating to move material from one or more dig locations to one ormore dump locations. The machine routing and planning system 117 may beconfigured to perform the planning operation while optimizing certainperformance goals associated with the material movement process. Theseperformance goals may include minimizing the wait or idle time of theexcavators 11, minimizing the wait or idle time of the haul trucks 40 atthe load locations, minimizing the travel distance of the haul trucks,maximizing the output of material at the work site 100, or maximizing orminimizing any other goals. Some of the performance goals may result inminimizing operational costs, while others may maximize production. Insome instances, a combination of performance goals may be utilized tomaximize the efficiency or some other aspect of the material movementprocess.

The machine routing and planning system 117 may generate different plansdepending upon the number of each type of machine 10 that are availableand the desired performance goals. In one embodiment, as part of theplanning process, a cost may be associated with each type of machine. Inone embodiment, the cost may be a rate per hour. In another embodiment,the cost may be based upon a quantity of material. In embodiments, thequantity may be expressed as a function of weight or volume (e.g., arate per unit weight or a rate per unit volume).

The machine routing and planning system 117 may simulate the operationof a plurality of machines in order to determine the desired operationor routing for each haul truck 40. In some operations, it has been foundthat an efficient operation of a mine site results from minimizing theidle time of the excavators by providing a sufficient number of haultrucks. In such case, the machine routing and planning system 117 may beused to determine a desired number of haul trucks 40 necessary tominimize the idle time of the excavators 11 in view of the cost ofoperation of the haul trucks 40, the travel distances between the loadlocations 101 and the dump locations 102 as well as the otherperformance goals.

An additional factor that will impact the operation of the machines atthe work site is the amount of carryback material within the dump body44 of each haul truck 40. More specifically, upon performing each loadand dump cycle (i.e., loading a haul truck 40 and then dumping thematerial at a dump location 102), additional carryback material willtypically adhere to the dump body 44. As a result of the carrybackmaterial, the current or effective capacity or the amount of materialthat can be carried from a load location 101 to a dump location willdecrease as will the fuel efficiency on the return trip. Accordingly,the actual hourly cost of operation of the haul trucks 40 will increaseas a result of the carryback material. As the cost of operation of thehaul trucks 40 increases due to the carryback material, the economics ofthe operation at the work site may change.

The machine routing and planning system 117 may thus also be configuredto further optimize performance at the work site 100 in view of theamount of carryback material within each haul truck 40. In doing so, themachine routing and planning system 117 may monitor the amount ofcarryback material within each haul truck 40 and determine the currentor effective capacity of each haul truck. The machine routing andplanning system 117 may compare the productivity loss as a result of thecarryback material against the productivity loss as a result of taking ahaul truck out of service as part of the clean out operation to removecarryback material.

More specifically, as stated above, as the amount of carryback materialincreases, the effective capacity (i.e., the volume and/or weightavailable for carrying material within the dump body 44) decreases, thusincreasing the cost of operation of each haul truck 40. In one example,the machine routing and planning system 117 may revise or modify thecost of operation of each haul truck based upon the amount of carrybackmaterial within its dump body 44. To do so, the machine routing andplanning system 117 may determine an initial amount of carrybackmaterial within the dump body 44 of each haul truck 40 and thendetermine or access an initial effective capacity of each haul truckbased in part on the initial amount of carryback material. The machinerouting and planning system 117 may generate an initial materialmovement plan based upon the number of loading machines and haul trucksat the work site 100 or associated with a specific loading machine andthe capacity of each loading machine and the initial effective capacityof each haul truck. The excavators 11 and haul trucks 40 may then beoperated at the work site 100 by generating initial movement commandsignals to operate according to the initial material movement plan.

As the haul trucks 40 are operated at the work site 100, they will beloaded, moved about the work site, unloaded, and occasionally cleanedout at a clean out station 107, 108. During such operation, the amountof carryback material within the dump body of each haul truck 40 willchange. Accordingly, a carryback monitoring system 60 may be used todetermine a current amount of carryback material within the dump body 44of each haul truck 40. The machine routing and planning system 117 mayaccess a modified effective capacity of each haul truck 40 based in parton the current amount of carryback material within each haul truck andgenerate a modified material movement plan based upon the number ofloading machines and haul trucks and the modified effective capacity ofeach haul truck. The excavators 11 and haul trucks 40 may then beoperated at the work site 100 by generating modified movement commandsignals to operate according to the modified material movement plan.

During operation, the machine routing and planning system 117 maycompare the productivity loss as a result of the amount of carrybackmaterial within each haul truck 40 against the productivity loss as aresult of taking one or more haul trucks out of service as part of aclean out operation to remove carryback material. In doing so, theproductivity loss as a result of taking the haul truck out of servicemay include costs associated with cleaning out the interior surface ofthe dump body such as the cost to operate the clean out mechanism andthe costs associated with travel time to and from a clean out station107, 108. Further, the productivity loss as a result of the amount ofcarryback material may be based in part upon a distance between loadlocations 101 and dump locations 102.

While performing the analysis of comparing the productivity loss due tocarryback material within the haul trucks 40 against the productivityloss due to clean out operations, the machine routing and planningsystem 117 determine a total unit cost of operation for the machines atthe work site and compare the total unit costs. The total unit costs maybe expressed in any desired manner. In one example, the total unit costmay be expressed as a cost per unit time. In another example, the totalunit cost may be expressed as a cost based on quantity of materialmoved. In such case, the quantity of material moved may be expressed asa cost per unit volume or as a cost per unit weight.

In another example, the machine routing and planning system 117 mayadjust the amount (e.g., volume or weight) of material that may becarried by each haul truck 40 based upon the amount of carrybackmaterial. The machine routing and planning system 117 may thus adjustthe operation plan for the machines 10 with the haul trucks 40 routed bythe machine routing and planning system based upon the revised ormodified cost of or revised or modified available volume or weight ofmaterial that may be carried by each haul truck.

The machine routing and planning system 117 may also use materialcharacteristics of the material being moved to proactively manage orplan for clean out operations as result of carryback material. Morespecifically, some types of material or geology may be more prone tocarryback. In addition, weather conditions may also play a role in theamount of carryback. The machine routing and planning system 117 mayhave stored or access a database having expected carryback for eachconfiguration of haul truck 40 at a work site 100 based upon thecharacteristics of the material being moved and the weather conditionsat the work site. The database may include the expected amount ofcarryback material associated with each haul truck as function of thenumber of load/dump cycles. In some instances, the carryback informationwithin the database may also depend on the machine or type of machineused to load each haul truck 40.

Geology samples may be taken from locations at which future miningoperations will occur. Upon analyzing the samples, the materialcharacteristics may be stored within a database associated with themachine routing and planning system 117. Based upon the materialcharacteristics of the geology samples and the types of machines thatwill be performing the future mining operations, the expected amount ofcarryback may be anticipated—as well as preferred or desired removaloptions.

In one embodiment, the machine routing and planning system 117 may usethe anticipated carryback to more accurately plan for machine operationin terms of the number of required or desired haul trucks 40. In anotherembodiment, the machine routing and planning system 117 may use theexpected amount of carryback material to reduce the frequency ofscanning the dump bodies 44 of the haul trucks 40 during machineoperation. In other words, rather than using the perception system 35prior to the first load of each loading cycle, the machine routing andplanning system 117 may identify when the perception system should beused to scan the dump body. The machine routing and planning system 117may be configured to direct a haul truck 40 to a scanning process aftera specified number of load/dump cycles and the specified number may bebased upon the material characteristics of the material being moved.

The machine routing and planning system 117 may also be configured todirect the haul truck 40 to a scanning process based upon the weight ofthe carryback material within the haul truck based upon payloadestimation from the payload estimation system 57. More specifically, thepayload estimation system 57 may determine the weight of the carrybackmaterial within the dump body 44. Based upon the materialcharacteristics of the material being moved, the machine routing andplanning system 117 may determine the volume of material within the dumpbody. The machine routing and planning system 117 may equate the volumeof carryback material to a percentage of the capacity of the dump body44 and determine that a clean out operation is desired. In such case,the machine routing and planning system 117 may direct the haul truck 40to a perception system 35 to perform a scanning operation and then to aclean location for a clean out operation.

Still further, based upon the material characteristics of the materialbeing moved, the machine routing and planning system 117 may determinethe type of clean out mechanism to be used. For example, water cannons70 may be better suited to remove some materials than others. Inaddition, the material characteristics may be used to determine theoperating characteristics and/or path of the clean out process. Forexample, the flow rate and pressure of the fluid as well as the rate atwhich the nozzle 73 traverses its desired path. Further, the materialcharacteristics may also be used to improve or optimize the pathtraveled by any type of clean out mechanism.

In an alternate or further embodiment, the control system 115 mayinclude a carryback clean out planning system 62 (FIG. 1) that isoperative to adjust or modify the carryback threshold of each haul truck40 based upon performance or operating conditions at the work site 100.As a first example, the carryback threshold may be set at a first value.In such case, each time the amount of carryback material in a dump body44 exceeds the clean out threshold, the haul truck 40 may be designatedfor a clean out operation. However, if at least one haul truck 40 istaken out of service (e.g., an operator is on a break, a machine isbeing refueled, a machine is our for service or repair, or a machine hasbeen misrouted), a fewer number of haul trucks may be available and thecarryback clean out planning system 62 may increase the carrybackthreshold so that a greater amount of carryback material is requiredbefore a machine is designated for clean out. By increasing thecarryback threshold, the likelihood is reduced that an excavator 11 willbe idle while waiting for a haul truck 40.

If a second haul truck 40 is taken out of service, the carrybackthreshold may be reduced again. As haul trucks 40 are returned toservice, the carryback threshold may be increased to or towards theoriginal carryback threshold.

In an example, the carryback threshold may be set at 10% of the volumeof the dump body 44. As each haul truck 40 is taken out of service, thecarryback clean out planning system 62 may increase the carrybackthreshold by 5%. Thus, the first haul truck removed from service resultsin an increase to 15%. The second haul truck 40 removed from serviceresults in the carryback threshold being increased to 20%.

The increases and decreases in the carryback threshold may or may not belinear. For example, upon removing a first haul truck 40 from service,the carryback threshold may increase by a first amount. Upon removing asecond haul truck 40 from service, the carryback threshold may beincreased by a second, greater amount. Using the example set forthabove, the removal of a first haul truck 40 from service will result inany increase in the carryback threshold to 15% but the removal of asecond haul track will result in an increase in the carryback thresholdto a number greater than 20%. By doing so, the carryback monitoringsystem 60 is less likely to designate a haul truck for a clean outoperation.

In an alternate embodiment, the machine routing and planning system 117may be configured to continue to direct haul trucks designated for cleanout between load locations 101 and dump locations 102. The machinerouting and planning system 117 may be configured to release haul trucks40 designated for clean out after comparing the cost of running oroperating the haul trucks in a less efficient manner with thesubstantial carryback against the potential cost of a excavator 11 beingidle.

Similarly, if one of the loading machines such as the excavators 11 isout of service, it may be desirable to reduce the carryback threshold toincrease the efficiency of the material moving process. In an example,removing an excavator 11 from operation may result in the carrybackthreshold being lowered from 10% to 5%.

INDUSTRIAL APPLICABILITY

The industrial applicability of the systems described herein will bereadily appreciated from the forgoing discussion. The foregoingdiscussion is applicable to systems used with machines such as haultrucks 40 that haul material at a work site 100. Such work sites mayinclude a mining site, a landfill, a quarry, a construction site, aroadwork site, or any other area in which material is transported.Carryback material located within the dump body 44 of a haul truck 40may reduce the operating efficiency of the material moving process.

Referring to FIG. 8, a flowchart of the operation of a process fordetermining, in an autonomous or semi-autonomous manner, whether thedump body 44 of a haul truck 40 should be designated for a clean outoperation. At stage 130, one or more carryback thresholds may be storedwithin controller 116. The carryback threshold may define a percentageof an empty dump body 44 or a volume of material. In an embodiment, ifthe carryback threshold is defined in terms of a percentage, thecarryback thresholds may be identical for all of the haul trucks 40operating at the work site 100. In other embodiments, and particularlyif the carryback threshold is defined in terms of a volume of material,the carryback threshold may be different for different haul trucks 40.

In some instances, multiple carryback thresholds may be stored for eachhaul truck 40. The multiple carryback thresholds could be used as partof a prioritization scheme to prioritize a subsequent clean outoperation. For example, a first carryback threshold having a firstpercentage and a second carryback threshold having a second, higherpercentage could be used with each haul truck 40. Upon exceeding thefirst threshold, the haul truck may be designated for a clean outoperation. Depending upon the operation of other machines at the worksite 100, such clean out operation may not occur immediately. In suchcase, the haul truck 40 may continue to operate at the work site 100transporting material between the load location 101 and the dumplocation 102. If the amount of carryback material within the dump body44 continues to increase, the amount of carryback material mayeventually exceed the second percentage. Upon exceeding the secondcarryback threshold, the haul truck 40 may receive a higher priority fora clean out operation.

At stage 131, a reference profile for each dump body 44 may be storedwithin the controller 116. Each reference profile may be associated witha unique identification code or other identifier associated with eachhaul truck 40 and as maintained within a database associated with themachine routing and planning system 117. The machines 10 may be operatedat the work site 100 at stage 132. In doing so, the loading machinessuch as excavators 11 may load haul trucks 40 at load locations 101 withmaterial. The loaded haul trucks 40 may then travel to the dumplocations 102 where the material is dumped. The empty haul trucks 40 maythen returned back to the load locations 101 to begin the next load/dumpcycle.

After an empty haul truck 40 is positioned at a load location 101, aloading machine such as an excavator 11 may move its bucket 17 filledwith material to a position above the dump body 44. Since the perceptionsensor such as camera system 36 may be positioned on the stick member 23adjacent the bucket 17, moving the excavator in this manner positions atstage 133 the camera system over the dump body 44.

Upon positioning the haul truck 40 adjacent the excavator 11, theidentity of the haul truck 40 and thus the dump body 44 may becommunicated at stage 134 to the controller 116. In one embodiment, thewireless communications system on board the haul truck 40 maycommunicate the identifying code of the haul truck to the controller 116and the controller may use the identifying code to identify the dumpbody 44. At stage 135, the controller 116 may determine the referenceprofile of the dump body 44 of the haul truck 40 based upon theidentifying code of the haul truck.

At stage 136, the pose of the dump body 44 may be determined. Theposition or pose of the dump body 44 may be determined from the dumpbody pose signals from the haul truck pose sensor 55. The currentprofile of the interior surface 46 of the dump body 44 may be determinedat stage 137 by the camera system 36. At stage 138, the pose of thecamera system 36 may be determined based upon implement system pose datafrom the implement system pose sensor 33 and the kinematics of theimplement system 12.

The differences between the reference profile and the current profile ofthe interior surface 46 of the dump body 44 may be determined at stage139. In one embodiment, the reference profile may be depicted as anelectronic map relative to the work site 100 and the current profile mayalso be depicted as an electronic map relative to the work site. The twoelectronic maps may be compared with the difference reflecting thecarryback material retained within the interior of the dump body 44.

At decision stage 140, the controller 116 may determine whether thedifference between the reference profile and the current profile exceedsthe carryback threshold. If the carryback threshold is not exceeded, themachines 10 may continue to operate and stages 132-140 repeated. If thecarryback threshold is exceeded, the haul truck 40 may be designated bythe controller 116 at stage 141 for a clean out operation. In someinstances, the haul truck 40 may be directed to a clean out siterelatively quickly. In other instances, the haul truck 40 may continueto operate along with the other machines and stages 132-140 repeateduntil the haul truck is directed to a clean out site.

Referring to FIG. 9, a flowchart of an autonomous or semi-autonomousclean out operation is depicted. At stage 145, a reference profile foreach dump body 44 may be stored within the controller 116. Eachreference profile may be associated with a unique identification code orother identifier associated with each haul truck 40. The kinematic modeland operating characteristics of the clean out mechanism such as theexcavator 111 may be stored within controller 116 at stage 146. Inembodiments utilizing other types of clean out mechanisms, such as thewater cannon 70, a kinematic model may not be stored.

The dump body 44 of the haul truck 40 to be cleaned out may bepositioned at a desired clean out location and in a desired orientationat stage 147. In an embodiment, the hydraulic cylinders 50 may be fullyextended to position the dump body 44 at its fully raised position toassist in the clean out process. In other embodiments, the hydrauliccylinders 50 may be only partially extended to only partially raise thedump body 44.

At stage 148, the identity of the haul truck 40 and thus the dump body44 may be communicated to the controller 116. In one embodiment, thewireless communications system on-board the haul truck 40 maycommunicate the identifying code of the haul truck to the controller 116and the controller may use the identifying code to identify the dumpbody 44.

The controller 116 may access at stage 149 an electronic map of thecarryback material disposed within the interior surface 46 of the dumpbody 44. In one embodiment, the electronic map may be generated duringan autonomous or semi-autonomous process of determining whether a cleanout operation is desired or necessary such as set forth in the flowchartof FIG. 8 above. In an embodiment in which a dump body 44 has beendesignated for a clean out operation without generating an electronicmap of the carryback material (e.g., with a manual designation),electronic map of the carryback material may be generated at the cleanout station 107, 108.

The clean out mechanism such as excavator 111 may be positioned adjacentthe dump body 44 as desired at stage 150. At stage 151, the pose of thedump body 44 may be determined. The position or pose of the dump body 44may be determined from the dump body pose signals from the haul truckpose sensor 55.

At stage 152, the pose of the clean out implement such as bucket 17 maybe determined based upon implement system pose signals or data from theimplement system pose sensor 33 and the kinematics of the implementsystem 12. In other words, the implement system pose sensor 33 operatesas a clean out system pose sensor and generates clean out implement posesignals that are used with the kinematics to determine the pose of theclean out implement.

The controller 116 may generate at stage 153 a path to move the bucket17 to physically engage or contact the carryback material that is stuckto the interior surface 46 of the dump body 44. The controller 116 maygenerate at stage 154 movement command signals to move the bucket 17along the path to perform a clean out operation on the interior surface46 of the dump body 44.

In some embodiments, the operation set forth in stages 145-154 may beterminated upon the completion of stage 154. In other embodiments, anadditional scanning operation may be performed at stage 155. Thescanning operation may be performed with a perception sensor such ascameras system 36 to generate an updated current profile of the interiorsurface 46 of the dump body 44 as described above. The updated currentprofile together with the pose of the perception sensor may be used togenerate an updated electronic map of the current profile relative tothe work site 100. The updated electronic map of the current profilerelative to the work site 100 may be compared to the an electronic mapof the reference profile relative to the work site to generate anupdated electronic map of the carryback material within the dump body44. The updated electronic map of the carryback material may be comparedto a carryback threshold at stage 156 to determine whether any furtherclean out operations are required. If no further clean out operationsare required, the haul truck 40 may be returned to operation at the worksite 100. If further clean out is required, stages 153-156 may berepeated.

Referring to FIG. 10, a flowchart of an aspect of the operation of themachine routing and planning system 117 is depicted. At stage 160, aplurality of carryback thresholds may be stored within or accessed bythe controller 116. Each carryback threshold may be expressed in anymanner such as, for example, as a percentage of the volume of an emptydump body. A different carryback threshold may be used based upon themix of loading machines and haul trucks 40 being used at the work site100. For example, it may be desirable to use a lower carryback thresholdwith a greater number of haul trucks 40 is assigned to each excavator 11and a relatively higher carryback threshold when a smaller number ofhaul trucks is assigned to each excavator. With a higher carrybackthreshold each haul truck 40 is less likely to be designated for a cleanout operation. Accordingly, a greater number of haul trucks 40 willremain in service, thus reducing the likelihood that a loading machinesuch as an excavator 11 will be idle.

As described above, the plurality of carryback thresholds may beidentical for each haul truck 40 or may be different, such as dependingupon the size and/or configuration of the haul truck or its dump body44. In some instances, the carryback thresholds may depend upon the typeof material being hauled.

At stage 161, the controller 116 may determine an initial number ofmachines including the number of loading machines and haul trucks 40operating at the work site 100. At stage 162, the controller 116 mayselect or assign a carryback threshold to each haul truck 40 based uponthe initial number of loading machines and haul trucks as well as themix of loading machines and haul trucks operating at the work site 100.Inasmuch as the ratio of haul trucks to loading machines may bedifferent at different locations at the work site 100, differentcarryback thresholds may be used at different locations at the worksite. For example, a first carryback threshold may be used with all ofthe haul trucks 40 assigned to a first excavator 11 and a secondcarryback threshold used with all of the haul trucks assigned to asecond excavator.

The machine routing and planning system 117 may generate at stage 163 aninitial material movement plan for operating machines such as theexcavators 11 and haul trucks 40 at the work site based upon the initialnumber of machines operating at the work site 100. The initial materialmovement plan may also be based upon the initial carryback thresholdthat was selected based upon the initial number of loading machines andhaul trucks operating at the work site 100.

The machines may be operated and moved about the work site 100 at stage164 according to the initial material movement plan. To do so, thecontroller 116 (e.g., excavator controller 31, haul truck controller 53)may generate initial movement command signals to direct the movement ofthe machines.

As the haul trucks 40 perform each load/dump cycle, carryback materialmay tend to build up on the interior surface 46 of the dump body 44 ofeach haul truck. Accordingly, it may be desirable, at times, to removeone or more haul truck 40 from service so that a clean out operation maybe performed. In addition, other haul trucks 40 may be removed fromservice for other reasons including an operator taking a break, amachine being refueled, a machine requires service or has broken down,or a machine has been misrouted. In such case, the number of haul trucksassigned to each loading machine may be reduced. In other instances, aloading machine such as an excavator 11 may be removed from service forany of a plurality of reasons. In those instances, the number of haultrucks 40 assigned to each of the remaining loading machines may beincreased.

From the foregoing, it may be understood that the ratio or mix of theloading machines and haul trucks 40 may change during the course ofoperation at a work site 100. Accordingly, at decision stage 165, thecontroller may determine whether the number of operating machines at thework site has changed and thus whether the mix or ratio of loadingmachines and haul machines has changed. If the number of machinesoperating at the work site 100 has not changed (and thus the ratio ofmachines has not changed), the machines may continue to operate basedupon the initial material movement plan and stages 164-165 repeated.

If the number of machines operating at the work site 100 has changed andthus the ratio has changed, the machine routing and planning system 117may generate a modified initial material movement plan in view of thenew number of machines and stages 162-165 repeated. More specifically,at stage 162, the controller 116 may select or assign a new or modifiedcarryback threshold to each haul truck 40 based upon the new or modifiednumber of loading machines and haul trucks as well as the mix of loadingmachines and haul trucks operating at the work site 100. At stage 163 anew or modified material movement plan may be generated based upon themodified number of machines operating at the work site 100. At stage164, the machines may be operated and moved about the work site 100according to the modified material movement plan by generating modifiedmovement command signals to direct the movement of the machines.

Referring to FIG. 11, a flowchart of another aspect of the operation ofthe machine routing and planning system 117 is depicted. At stage 170,the cost of operation and/or the capacity (e.g., volume) of each machineoperating at the work site 100 may be stored within or accessed by thecontroller 116. In doing so, the cost of operation and/or capacity ofeach loading machine such as excavators 11 may be stored. In addition,the cost of operation and/or the capacity of each haul truck 40 may alsobe stored. Since the cost of operation and/or capacity of each haultruck 40 may vary or change depending upon the amount of carrybackmaterial within the dump body 44, the controller 116 may include aplurality of costs of operation for each haul truck 40, with eachcorresponding to an amount of carryback material. The cost of operationmay be expressed as a function of time, the volume of the materialmoved, the weight of the material moved, or in any other desired manner.

A system such as carryback monitoring system 60 may be used at stage 171to determine the amount of carryback material within the dump body 44 ofeach haul truck 40. The process at stage 70 may correspond to scanningor otherwise determining the amount of carryback material within one ormore dump bodies 44 together with accessing stored data from previousscans or determinations of the amount of carryback material within otherdump bodies. In other words, the interior surface 46 of each dump body44 may not be scanned at the same time.

At stage 172, the machine routing and planning system 117 may generate amaterial movement plan for operating the machines such as the excavators11 and haul trucks 40 at the work site 100 based upon one or morefactors including the amount of carryback material within each haultruck 40. More specifically, in an embodiment, the machine routing andplanning system 117 may be configured to plan the routes of the haultrucks 40 based upon the effective capacity of each haul truck basedupon the amount of carryback material within each haul truck.

In some instances, the machine routing and planning system 117 mayfurther compare at decision stage 173 the productivity loss as a resultof the carryback material within each haul truck 40 against theproductivity loss as a result of taking one or more haul trucks out ofservice as part of a cleanout operation to remove carryback material. Inone example, the machine routing and planning system 117 may determine atotal unit cost of operation for the machines at the work site 100 (or aportion of the work site such as a specific loading machine and haultrucks dedicated to the specific loading machine) in view of thecarryback material. Various manners of determining the total unit costof operation are contemplated. Further, various other manners ofoptimizing the performance of the machines at the work site 100 otherthan based on cost are contemplated.

As the machine routing and planning system 117 operates, it maydetermine whether the cost of operation with the carryback materialwithin the haul trucks 40 exceeds the costs associated with a cleanoutoperation. More specifically, the machine routing and planning system117 may determine the total unit cost of operation including haul trucks40 with carryback material. The machine routing and planning system 117may also determine the total unit cost associated with removing one ormore haul trucks 40 from material moving operations and performing aclean out operation while the remaining haul trucks continue to operate.Based upon the determination of the total unit cost of operationincluding haul trucks 40 with the carryback material and the total unitcost of operation based on the remaining haul trucks while removing oneor more haul trucks for a clean out operation, the machine routing andplanning system 117 may determine whether to re-route or direct one ormore haul trucks to a clean out station 107, 108.

If the cost of operation with the carryback material exceeds the costsassociated with a cleanout operation at decision stage 173, movementcommand signals may be generated to direct one or more haul trucks 40 atstage 174 to a clean out station 107, 108. In such case, the materialmovement plan generated at 172 may route at stage 175 the remaining haultrucks 40 to optimize the performance at the work site 100. Suchoptimization may include one or more optimization parameters or goalssuch as reducing total costs, maximizing the amount of material beingmoved, or any other desired parameter or goal.

As each clean out operation is completed, the empty haul truck 40 may bereturned at stage 176 to operation by directing the empty haul truck tothe desired load location 101. Upon returning the empty haul truck 42operation, a new analysis of the carryback material in each haul truckand new material movement plan may be generated with stages 171-177repeated.

If the cost of operation with the carryback material does not exceed thecosts associated with a cleanout operation at decision stage 173,movement command signals may be generated at stage 177 to route all ofthe haul trucks 40 to optimize the performance at the work site 100. Thehaul trucks 40 may operate at the work site 100 and stages 171-177repeated each time a haul truck is scanned or the amount of carrybackmaterial is otherwise determined.

From the foregoing, it may be understood that the machine routing andplanning system 117 may continuously operate in order to optimize theperformance at the work site 100. In doing so, each time there is achange in the amount of carryback material, it may be desirable togenerate a new material movement plan and/or determine whether it isdesirable to send one or more haul trucks 40 to a clean out operation.Changes in the amount of carryback material may occur, for example, eachtime a dump body 44 is scanned or after a dump body is cleaned out.

It will be appreciated that the foregoing description provides examplesof the disclosed system and technique. All references to the disclosureor examples thereof are intended to reference the particular examplebeing discussed at that point and are not intended to imply anylimitation as to the scope of the disclosure more generally. Alllanguage of distinction and disparagement with respect to certainfeatures is intended to indicate a lack of preference for thosefeatures, but not to exclude such from the scope of the disclosureentirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context.

Accordingly, this disclosure includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by thedisclosure unless otherwise indicated herein or otherwise clearlycontradicted by context.

1. A machine routing and planning system for mobile machines at a worksite, the system comprising: a plurality of haul trucks, each haul truckhaving a dump body for hauling material, the dump body having aninterior surface; at least one loading machine for loading material intothe dump body of each haul truck; and a controller configured to: accessan initial number of loading machines and haul trucks operating at thework site; access an initial carryback threshold for the interiorsurface of each haul truck based on the initial number of loadingmachines and haul trucks operating at the work site; generate an initialmaterial movement plan based upon the initial number of loading machinesand haul trucks and the initial carryback threshold; generate initialmovement command signals to operate the loading machines and haul trucksat the work site based upon the initial material movement plan; access amodified number of loading machines and haul trucks operating at thework site; access a modified carryback threshold for the interiorsurface of each haul truck based on the modified number of loadingmachines and haul trucks operating at the work site; generate a modifiedmaterial movement plan based upon the modified number of loadingmachines and haul trucks and the modified carryback threshold; andgenerate modified movement command signals to operate the loadingmachines and haul trucks at the work site based upon the modifiedmaterial movement plan.
 2. The system of claim 1, wherein the modifiedcarryback threshold is greater than the initial carryback threshold upona decrease in a number of haul trucks operating at the work site withouta change in a number of loading machines operating at the work site. 3.The system of claim 1, wherein the modified carryback threshold is lessthan the initial carryback threshold upon an increase in a number ofhaul trucks operating at the work site without a change in a number ofloading machines operating at the work site.
 4. The system of claim 1,wherein a difference between the initial carryback threshold and themodified carryback threshold is linear relative to a change in a numberof haul trucks operating at the work site.
 5. The system of claim 1,wherein a difference between the initial carryback threshold and themodified carryback threshold is nonlinear relative to a change in anumber of haul trucks operating at the work site.
 6. The system of claim1, wherein each material movement plan is determined based upon a costof operating each machine.
 7. The system of claim 6, wherein the cost ofoperating each machine is expressed as a cost per unit time.
 8. Thesystem of claim 6, wherein the cost of operating each machine isexpressed as a cost based on quantity of material moved.
 9. The systemof claim 8, wherein the cost based on quantity of material moved isexpressed as a cost per unit volume.
 10. The system of claim 9, whereinthe cost based on quantity of material moved is expressed as a cost perunit weight.
 11. The system of claim 1, further comprising a carrybackmonitoring system to determine an amount of carryback material withinthe dump body of each haul truck.
 12. The system of claim 11, whereineach material movement plan is based upon an effective volume of thedump body of each haul truck.
 13. The system of claim 11, wherein eachmaterial movement plan includes designating each haul truck for a cleanout operation upon the amount of carryback material exceeding a currentcarryback threshold, and directing a haul truck to a clean out stationafter designating the haul truck for the clean out operation.
 14. Thesystem of claim 13, wherein each material movement plan includesdirecting haul trucks to the clean out station based upon aprioritization scheme.
 15. A method of machine routing and planning formobile machines at a work site comprising: accessing an initial numberof loading machines and haul trucks operating at the work site, the haultrucks having a dump body for hauling material, the loading machinesconfigured for loading material into the dump body of each haul truck;accessing an initial carryback threshold for an interior surface of eachhaul truck based on the initial number of loading machines and haultrucks operating at the work site; generating an initial materialmovement plan based upon the initial number of loading machines and haultrucks and the initial carryback threshold; generating initial movementcommand signals to operate the loading machines and haul trucks at thework site based upon the initial material movement plan; accessing amodified number of loading machines and haul trucks operating at thework site; accessing a modified carryback threshold for the interiorsurface of each haul truck based on the modified number of loadingmachines and haul trucks operating at the work site; generating amodified material movement plan based upon the modified number ofloading machines and haul trucks and the modified carryback threshold;and generating modified movement command signals to operate the loadingmachines and haul trucks at the work site based upon the modifiedmaterial movement plan.
 16. The method of claim 15, wherein upon adecrease in a number of haul trucks operating at the work site without achange in a number of loading machines operating at the work site,increasing the initial carryback threshold to define the modifiedcarryback threshold.
 17. The method of claim 15, wherein upon anincrease in a number of haul trucks operating at the work site without achange in a number of loading machines operating at the work site,decreasing the initial carryback threshold to define the modifiedcarryback threshold.
 18. The method of claim 15, further comprisingdetermining an amount of carryback material within the dump body of eachhaul truck.
 19. The method of claim 18, further comprising designatingeach haul truck for a clean out operation upon the amount of carrybackmaterial exceeding a current carryback threshold and directing a haultruck to a clean out station after designating the haul truck for theclean out operation.
 20. The method of claim 15, further comprisingdetermining an amount of carryback material within the dump body of eachhaul truck and generating each material movement plan based upon aneffective volume of the dump body of each haul truck.